Self-actuating brake for intermittently operating mechanism

ABSTRACT

TO PREVENT DAMAGE BY ROTATING MECHANISMS WHICH INTERMITTENTLY START AND STOP MANY TIMES PER MINUTE, AS FOR EXAMPLE IN A PITNEY-BOWES STAMP METER MACHINE, THERE IS PROVIDED BRAKING MECHANISM WHICH IS SELF-ACTUATING AND EFFECTIVE ONLY IN THE RELATIVELY SHORT INTERVAL OF TIME BEFORE THE STOPPAGE OF ROTATION OCCURS DURING EACH CYCLE OF OPERATIONS. THE BRAKING MECHANISM IS IN THE FORM OF A SPECIAL GEAR WHICH FRICTIONALLY ENGAGES A STATIONARY ELEMENT TO CAUSE A DRAG ON THE ROTATING MECHANISM DURING THE FINAL 25% OF TRAVEL OF THE ROTATING MECHANISM IMMEDIATELY BEFORE THE ROTATING MECHANISM ARRIVES AT THE HOME OR REST POSITION IN EACH CYCLE OF OPERATION.

Nov. 23, 1971 M. Houss 3,621,781

SELF-ACTUATING BRAKE FOR INTERMITTENTLY OPERATING MECHANISM Filed June 12, 1970 2 Sheets-Shoot 1 MAX H0055 By M MW ITTORNEY NOV. 23, 1971 ouss 3,621,131

SELF-ACTUATING BRAKE FOR INTERMITIENTLY OPERATING MECHANISM Filed June 12. 1970 2 Sheets-Sheet 2 FIG.2.

INVENTOH MAX #0055 By H United States Patent r 3,621,731 SELF-ACTUATING BRAKE FOR IN TERMITTENTLY OPERATING MECHANISM Max Houss, 1123 E. 26th St., Brooklyn, N.Y. 11210 lFiled June 12, 1970, Ser. No. 45,857 Int. Cl. E1611 5710; B60t13/04 U.S. Cl. 74-4115 7 Claims ABSTRACT OF THE DISCLOSURE To prevent damage by rotating mechanisms which intermittently start and stop many times per minute, as for example in a Pitney-Bowes stamp meter machine, there is provided braking mechanism which is self-actuating and effective only in the relatively short interval of time before the stoppage of rotation occurs during each cycle of operations. The braking mechanism is in the form of a special gear which frictionally engages a stationary element to cause a drag on the rotating mechanism during the final 25% of travel of the rotating mechanism immediately before the rotating mechanism arrives at the home or rest position in each cycle of operation.

BACKGROUND The invention is herein described in connection with postage meter mechanism. It is known to feed printed matter sequentially and rapidly through a meter machine. One such machine is a postage meter manufactured and sold by Pitney-Bowes Company and this machine includes an attachment in which there is placed any desired amount of prepaid postage purchased from the government. This known attachment prints by the impression of inked dies, postage upon sequentially and rapidly advancing mail matter. In my US. Pat. 3,393,113 there is described a postage stamp afiixer (as contrasted to a die stamp imprinting postage attachment) which afiixes stamps on the mailing printed matter which is fed sequentially through the machine. In the operation of such machines, a trip lever responds to the impact or passage of the advancing printed matter, such as an envelope or a card, to actuate a clutch-driven drive shaft for a single revolution. The trip lever is actuated once each time an envelope or card passes in its travel to the stamp meter or aflixer, and each actuation of the lever operates a spring-loaded clutch which, in turn, causes the drive shaft to rotate one revolution; hence, the drive shaft, by suitable gears, is intermittently driven for a single cycle or revolution.

After the postage is stamped on the mailing matter, or in the case of the attachment described in my aformentioned US. patent, after the stamp is fed, moistened, severed and afiixed to the envelope, the rotating head rotates to its home or rest position in which it is ready for another cycle of operations. To stop the rotating head in its home or rest position, there is provided a steel stop latch which is located in the Pitney-Bowes meter base in the clutch portion thereof. The stop latch is in the form of two extending prongs which physically stop the clutch from rotating when the head is in the home position. When the head is tripped by the advancing printed matter, for example by envelopes, the stop latch is retracted to permit a new cycle of rotation of the head, until such time during the cycle of rotation when the stop latch again is caused to position itself to restrain movement of the rotating head when it reaches the home or rest position. This cycle of operations repeats itself at a rate of about 12,000 times per hour. During the last 25% of the driving cycle, the clutch of the driving mechanism located in the base is in a released position. This method of enabling the rotating head to start and stop is known in the art and no claim is being made thereto. It has been found, however, that this type of continual stop and go rotational motion at the required speeds damages or tends to damage the stop mechanism.

SUMMARY OF INVENTION To avoid this damage I have devised a self-actuating brake mechanism which is effective at a desired interval, particularly in the relatively short interval of time immediately before the stoppage of the rotation occurs. Stated in other words, my self-actuating brake mechanism becomes effective during the last part of the cycle of rotation of the rotating head, preferably during the last or final 25 of rotation of the head in order to slow down the speed of the gear train in the 12 to 9 oclock position by appreciably reducing the inertia of the drive shaft. Since the clutch is in the released position during the final part of rotation of the rotating head in each cycle of operation the overall speed capability of the machine is not affected. One form of the invention, hereinafter described, makes use of a rotatable drag gear which frictionally engages a stationary element which, in turn, exerts pressure against the side of the gear to cause a drag on the rotation of the gear in proportion to the magnitude of the aforesaid pressure. Specifically, in accordance with the embodiment of the invention herein described, a specially constructed sector gear, rotatable with the gear train, engages the drag gear only when the rotatable head is in the final 25 of its rotational travel before reaching the stop position.

BRIEF DESCRIPTION OF DRAWING A detailed description of the invention follows, in conjunction with a drawing wherein:

FIG. 1 is a perspective view of only that portion of the postage meter or stamp afiixer attachment necessary for an understanding of the invention. The sector gear of the Make of the invention is shown in the position in which it engages the drag gear. The sector gear is shown gear-linked to the drive shaft; and

FIG. 2 is a detail sectional view of FIG. 1.

Throughout the figures of the drawing the same parts are represented by the same reference numerals.

DETAILED DESCRIPTION The drawings illustrate only those parts of the gear train of the rotating mechanism and braking mechanism necessary for an understanding of the invention. The drive shaft 10 is intermittently operated by a spring-loaded clutch mechanism. The clutch mechanism and the trip lever which is actuated by the sequentially advancing mailing matter heretofore referred to are located in the base, not shown. Drive shaft 10 may intermittently operate at the rate of approximately 200 times per minute and is mounted in a bearing in a steel plate 12 and drives a gear 14 which, in turn, meshes with a gear 16 to drive a shaft 18 to which gear 16 is securely fastened. The ends of ro tatable shaft 18 are journaled in suitable bearings in /2 steel plates 12 and 22. Mounted on shaft 18- is a sector gear 20 which has equally spaced teeth, for example fifteen, covering only about 40% of its peripheral surface. These teeth on sector gear 20 are adapted to mesh with the teeth of a drag gear 24 during only the last 2 of rotational travel of the drive shaft in each cycle. One side of the drag gear 24 frictionally engages a stationary steel plate 26 which is securely fastened, as by screws, to a /2" steel plate 28. Steel plate 28 is attached to a /2" steel plate 30 and both are held in position by solid cylindrical steel bolts 32 and 34, extending between plates 12 and 22 and similar steel bolts, not shown, in the rear also extending between plates 12 and 22. A threaded stationary connecting rod 36 extends between and through steel plates 12 and 28 and 30, and through the hollow center of drag gear 24.

Drag gear 24 is milled out on its right side to provide a cone-shaped recess or countersunk area 40 in which rests a stationary cone-shaped steel plug 42. The cone-shaped plug 42 is keyed into a stationary keyed mass 43 which supports the threaded connecting rod 36 by means of a key 45. The cone-shaped steel plug 42 is concentrically positioned with respect to drag gear 24. Plug 42 exerts pressure on the drag gear 24. A coiled pressure spring 44 is held in compression between a pair of flat stationary steel washers, 46, 46. The left washer pushes against the fiat side of the cone-shaped steel plug 42 while the right Washer is forced against the spring 44 by the two threaded lock nuts 47. The degree of pressure exerted by the coil spring 44 against the side of the drag gear 24 via washer 46 and cone-shaped plug 42 is adjustable by adjusting the position of the lock nuts 47 along the length of the connecting rod 36.

In the operation of the invention, during the final of rotational travel in each cycle of rotation of the drive shaft 10, the teeth of the sector gear 20 engage the teeth of drag gear 24 and cause rotation of drag gear 24 against the frictional pressure exerted against its sides by stationary plate 26 and conical-shaped plug 42. During the meshing of sector gear 20 and drag gear 24 about 50% or the inertia of the drive shaft is reduced by the drag or brake action of gear 24. The resistance to motion of the drag gear 24 is in proportion to the pressure exerted on its sides by the plug 42 and its associated pressure spring 44. A longer or shorter period of drag or braking action may be obtained by changing the number of teeth on the sector gear 20. The precise positioning of the sector gear in its engagement with the drag gear enables timing of the drag effect on the rotating mechanism.

In the use of the invention on a Pitney-Bowes type of postage meters or stamp afiixing device of my US. Patent 3,393,113, suitable gears, not shown, on shaft 18 adjacent and to the right of steel plate 22 will, in turn, rotate a shaft journaled in bearings in plates 22 and for driving the rotating head. These gears and shaft have not been shown because the illustration thereof is not necessary to an understanding of the present invention, but this last shaft will pass through plate 22 and correspond to shaft S shown in FIG. 11 of my aforesaid US. Patent 3,393,113.

The considerable reduction in inertia (about 50%) of the drive shaft during the final 25% of rotational travel thereof, due to the braking action of the invention, avoids completely or reduces to a minimum any tendency toward damage of the stop mechanism.

What is claimed is:

1. Intermittently operating mechanism comprising a moveable part which repeats a cyclical start and stop movement a plurality of times per minute, braking mechanism for said part, means to effectively apply said braking mechanism to said part during an appreciable portion of the travel of said part in each cycle of operations but only shortly before the part arrives at the stop position, and means for supporting said moveable part, braking mechanism and said first means in cooperative relationships.

2. Intermittently operating mechanism according to claim 1, wherein said moveable part is a rotatable shaft driving a gear train, and said braking mechanism includes a sector gear mounted on said rotatable shaft, said sector gear having teeth covering only approximately 40% of the periphery thereof, a drag gear having teeth adapted to mesh with the teeth of said sector gear only during the final approximately 25 of rotational travel of said shaft in each cycle before the shaft reaches the stop position, said drag gear being spring-loaded to introduce frictional resistance to rotation thereof.

3. Intermittently operating mechanism according to claim 1, wherein said moveable part is a rotatable shaft driving a gear train, and said braking mechanism includes a sector gear mounted on said rotatable shaft, said sector gear having teeth covering only approximately 40% of the periphery thereof, a drag gear having teeth adapted to mesh with the teeth of said sector gear only during the final approximately 25 of rotational travel of said shaft in each cycle before the shaft reaches the stop position, said drag gear having one flat side frictionally engaging a stationary steel plate, the other side of said drag gear being milled out near its hollow center to provide a coneshaped recess, a stationary cone-shaped plug resting in said recess and concentrically positioned relative to said drag gear, a coiled spring exerting pressure on said plug, and means for adjusting the pressure exerted by said spring on said plug.

4. A postage stamp or metering attachment having a rotatable shaft driving a gear train adapted to cyclically start and stop approximately twelve thousand times per hour, braking mechanism for said rotatable shaft and gear train effective only during and extending over the final portion of rotational travel of said shaft in each cycle before arriving at the stop position, said braking mechanism including a sector gear mounted on said rotatable shaft, said sector gear having equally spaced teeth covering only approximately 40% of the peripheral surface thereof, a drag gear whose teeth cover its entire peripheral surface adapted to mesh with the teeth of said sector gear, said sector gear being so mounted on said rotatable shaft that it meshes with said drag gear only during and extending over the final approximately 25% of rotational travel of said shaft in each cycle before the shaft reaches the stop position, and a spring exerting pressure against said drag gear to introducer resistance to rotational movement of said drag gear.

5. A postage stamp or metering attachment according to claim 4, wherein said drag gear has one fiat side frictionally engaging a stationary steel plate, the other side of said drag gear being milled out near its hollow center to provide a cone-shaped recess, a stationary cone-shaped steel plug resting in said recess and concentrically positioned relative to said drag gear, a threaded stationary connect-rod passing through said plug and the center of said drag gear, a washer on said rod engaging said steel plug, a coiled spring around said rod, one end of said spring contracting said Washer, and a lock nut on said rod in engagement with the other end of said spring, whereby adjustment of the positioned of said nut affords adjustable pressure against said steel plug and drag gear.

6. A postage stamp or metering attachment having a rotatable shaft driving a gear train adapted to cyclically start and stop, braking mechanism for said rotatable shaft and gear train effective only during and extending over the final portion of rotational travel of said shaft in each cycle before arriving at the stop position, said braking mechanism including a sector gear driven by said rotatable shaft, said sector gear having equally spaced teeth covering less than one-half of the peripheral surface thereof, a drag gear whose teeth cover its entire peripheral surface adapted to mesh with the teeth of said sector gear, said sector gear being so mounted in relation to said rotatable shaft that it meshes with said drag gear only during and extending over the final portion of rotational travel of said shaft in each cycle before the shaft reaches the stop position, and a spring exerting pressure against said drag gear to introduce resistance to rotational movement of said drag gear.

7. Self-actuating brake mechanism for rotating mechanisms which intermittently start and stop, comprising a rotatable shaft which repeats a cyclical start and stop movement a plurality of times per minute, braking mechanism for said shaft including a sector gear having teeth on only a portion of its periphery, and a spring-loaded drag gear having teeth adapted to mesh With the teeth of said sector gear during only a portion of the time of rotation of said sector gear, and means responsive to rotation of said shaft for causing said sector gear to mesh with said drag gear only during and extending over the final portion of rotational travel of said shaft in each cycle before the shaft reaches the stop position.

References Cited UNITED STATES PATENTS 3,485,109 12/1969 Dunlap 74-411.5X 3,485,329 12/1969 Hauser 74411.5 X

10 LEONARD H. GERIN, Primary Examiner US. Cl. X.R. 

